/*

  * Copyright 2007 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.kew.engine.node;

 import java.util.ArrayList;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.kew.actionrequest.ActionRequestFactory;

 import org.kuali.rice.kew.actionrequest.ActionRequestValue;

 import org.kuali.rice.kew.engine.RouteContext;

 import org.kuali.rice.kew.engine.RouteHelper;

 import org.kuali.rice.kew.exception.RouteManagerException;

 import org.kuali.rice.kew.exception.WorkflowException;

 import org.kuali.rice.kew.routeheader.DocumentRouteHeaderValue;

 import org.kuali.rice.kew.rule.FlexRM;

 import org.kuali.rice.kew.rule.KRAMetaRuleEngine;

 import org.kuali.rice.kew.rule.RuleExpressionResult;

 import org.kuali.rice.kew.service.KEWServiceLocator;

 import org.kuali.rice.kew.util.Utilities;

 /**

  * Node that implements a KRAMetaRule, with multiple request/response phases

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class KRAMetaRuleNode extends IteratedRequestActivationNode {

         private static String SUPPRESS_POLICY_ERRORS_KEY = "_suppressPolicyErrorsRequestActivationNode";

         protected List<ActionRequestValue> generateUninitializedRequests(ActionRequestFactory arFactory, RouteContext context, RuleExpressionResult result) throws WorkflowException {

                 FlexRM flexRM = new FlexRM();

                 flexRM.makeActionRequests(arFactory, result.getResponsibilities(), context, result.getRule().getDefinition(), context.getDocument(), null, null);

                 return new ArrayList<ActionRequestValue>(arFactory.getRequestGraphs());

         }

         protected List<ActionRequestValue> initializeRequests(List<ActionRequestValue> requests, RouteContext context) {

                 // RequestNode.getNewActionRequests

                 List<ActionRequestValue> newRequests = new ArrayList<ActionRequestValue>();

                 for (Iterator iterator = requests.iterator(); iterator.hasNext();) {

                         ActionRequestValue actionRequest = (ActionRequestValue) iterator.next();

                         actionRequest = KEWServiceLocator.getActionRequestService().initializeActionRequestGraph(actionRequest, context.getDocument(), context.getNodeInstance());

                         saveActionRequest(context, actionRequest);

                         newRequests.add(actionRequest);

                 }

                 return newRequests;

         }

         @Override

         protected boolean generateNewRequests(boolean initial, RouteContext context, RouteHelper routeHelper)

         throws WorkflowException, Exception {

                 RouteNodeInstance nodeInstance = context.getNodeInstance();

                 RouteNode nodeDef = nodeInstance.getRouteNode();

                 // get the expression

                 Map<String, String> cfg = Utilities.getKeyValueCollectionAsMap(nodeDef.getConfigParams());

                 String expression = cfg.get("expression");

                 if (StringUtils.isEmpty(expression)) {

                         throw new WorkflowException("No meta-rule expression supplied in node " + nodeDef);

                 }

                 KRAMetaRuleEngine engine = new KRAMetaRuleEngine(expression);

                 // get the current statement

                 int curStatement = getCurStatement(nodeInstance);

                 engine.setCurStatement(curStatement);

                 if (engine.isDone()) {

                         return false;

                 }

                 // generate next round of action requests

                 RuleExpressionResult result = engine.processSingleStatement(context);

                 if (!result.isSuccess()) {

                         return false;

                 }

                 boolean suppressPolicyErrors = isSupressingPolicyErrors(context);

                 boolean pastFinalApprover = isPastFinalApprover(context.getDocument(), nodeInstance);

                 // actionRequests.addAll(makeActionRequests(context, rule, routeHeader, null, null));

                 // copied from parts of FlexRM and RequestsNode

                 ActionRequestFactory arFactory = new ActionRequestFactory(context.getDocument(), context.getNodeInstance());

                 List<ActionRequestValue> requests = generateUninitializedRequests(arFactory, context, result);

                 requests = initializeRequests(requests, context);

                 // RequestNode

                 if ((requests.isEmpty()) && nodeDef.getMandatoryRouteInd().booleanValue() && ! suppressPolicyErrors) {

                         LOG.warn("no requests generated for mandatory route - " + nodeDef.getRouteNodeName());

                         throw new RouteManagerException("No requests generated for mandatory route " + nodeDef.getRouteNodeName() + ":" + nodeDef.getRouteMethodName(), context);

                 }

                 // determine if we have any approve requests for FinalApprover checks

                 boolean hasApproveRequest = false;

                 for (Iterator iter = requests.iterator(); iter.hasNext();) {

                         ActionRequestValue actionRequest = (ActionRequestValue) iter.next();

                         hasApproveRequest = actionRequest.isApproveOrCompleteRequest() || hasApproveRequest;

                 }

                 // if final approver route level and no approve request send to exception routing

                 if (nodeDef.getFinalApprovalInd().booleanValue()) {

                         // we must have an approve request generated if final approver level.

                         if (!hasApproveRequest && ! suppressPolicyErrors) {

                                 throw new RuntimeException("No Approve Request generated after final approver");

                         }

                 } else if (pastFinalApprover) {

                         // we can't allow generation of approve requests after final approver. This guys going to exception routing.

                         if (hasApproveRequest && ! suppressPolicyErrors) {

                                 throw new RuntimeException("Approve Request generated after final approver");

                         }

                 }

                 // increment to next statement

                 nodeInstance.getNodeState("stmt").setValue(String.valueOf(curStatement + 1));

                 return !requests.isEmpty();

         }

         /**

          * @param nodeInstance the current node instance under execution

          * @return the meta-rule statement this node instance should process

          */

         protected static int getCurStatement(RouteNodeInstance nodeInstance) {

                 int statement = 0;

                 NodeState nodeState = nodeInstance.getNodeState("stmt");

                 if (nodeState == null) {

                         nodeState = new NodeState();

                         nodeState.setKey("stmt");

                         nodeState.setNodeInstance(nodeInstance);

                         nodeInstance.addNodeState(nodeState);

                 }

                 if (StringUtils.isEmpty(nodeState.getValue())) {

                         nodeState.setValue("0");

                 } else {

                         statement = Integer.parseInt(nodeState.getValue());

                 }

                 return statement;

         }

         @Override

         protected RequestFulfillmentCriteria getRequestFulfillmentCriteria(RouteContext routeContext) {

                 return super.getRequestFulfillmentCriteria(routeContext);

         }

         // -- copied from request node; a lot of this action request evaluating code should probably go into helper classes or factored into a common subclass

         /**

          * The method will get a key value which can be used for comparison purposes. If the node instance has a primary key value, it will be returned. However, if the node instance has not been saved to the database (i.e. during a simulation) this method will return the node instance passed in.

          */

         private Object getKey(RouteNodeInstance nodeInstance) {

                 String id = nodeInstance.getRouteNodeInstanceId();

                 return (id != null ? (Object) id : (Object) nodeInstance);

         }

         /**

          * Checks if the document has past the final approver node by walking backward through the previous node instances.

          * Ignores any previous nodes that have been "revoked".

          */

         private boolean isPastFinalApprover(DocumentRouteHeaderValue document, RouteNodeInstance nodeInstance) {

                 FinalApproverContext context = new FinalApproverContext();

                 List revokedNodeInstances = KEWServiceLocator.getRouteNodeService().getRevokedNodeInstances(document);

                 Set revokedNodeInstanceIds = new HashSet();

                 for (Iterator iterator = revokedNodeInstances.iterator(); iterator.hasNext(); ) {

                         RouteNodeInstance revokedNodeInstance = (RouteNodeInstance) iterator.next();

                         revokedNodeInstanceIds.add(revokedNodeInstance.getRouteNodeInstanceId());

                 }

                 isPastFinalApprover(nodeInstance.getPreviousNodeInstances(), context, revokedNodeInstanceIds);

                 return context.isPast;

         }

         private void isPastFinalApprover(List previousNodeInstances, FinalApproverContext context, Set revokedNodeInstanceIds) {

                 if (previousNodeInstances != null && !previousNodeInstances.isEmpty()) {

                         for (Iterator iterator = previousNodeInstances.iterator(); iterator.hasNext();) {

                                 if (context.isPast) {

                                         return;

                                 }

                                 RouteNodeInstance nodeInstance = (RouteNodeInstance) iterator.next();

                                 if (context.inspected.contains(getKey(nodeInstance))) {

                                         continue;

                                 } else {

                                         context.inspected.add(getKey(nodeInstance));

                                 }

                                 if (Boolean.TRUE.equals(nodeInstance.getRouteNode().getFinalApprovalInd())) {

                                         // if the node instance has been revoked (by a Return To Previous action for example)

                                         // then we don't want to consider that node when we determine if we are past final

                                         // approval or not

                                         if (!revokedNodeInstanceIds.contains(nodeInstance.getRouteNodeInstanceId())) {

                                                 context.isPast = true;

                                         }

                                         return;

                                 }

                                 isPastFinalApprover(nodeInstance.getPreviousNodeInstances(), context, revokedNodeInstanceIds);

                         }

                 }

         }

         public static boolean isSupressingPolicyErrors(RouteContext routeContext) {

                 Boolean suppressPolicyErrors = (Boolean)routeContext.getParameters().get(SUPPRESS_POLICY_ERRORS_KEY);

                 if (suppressPolicyErrors == null || ! suppressPolicyErrors) {

                         return false;

                 }

                 return true;

         }

         private class FinalApproverContext {

                 public Set inspected = new HashSet();

                 public boolean isPast = false;

         }

 }